Add collation from ICU4X

[mosuem]

Add collation from ICU4X, and adapt the other functionalities to the slightly changed API. This includes adding a build.dart script to download/build/fetch an icu4x binary, which is accessed at runtime by dart files symlinked from the icu4x repository (see the tools/ script for generating those).

---

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[github-actions]

Package publishing

Package	Version	Status	Publish tag (post-merge)
package:intl4x	0.8.0	ready to publish	intl4x-v0.8.0
package:intl	0.20.0-wip	WIP (no publish necessary)
package:intl_translation	0.20.0-wip	WIP (no publish necessary)
package:messages	0.2.0	already published at pub.dev
package:messages_builder	0.2.1	already published at pub.dev
package:messages_serializer	0.2.1	already published at pub.dev
package:messages_shrinker	0.2.2-wip	WIP (no publish necessary)
package:icu	0.0.0	(error) pubspec version (0.0.0) and changelog (null) don't agree

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[github-actions]

PR Health

Breaking changes ✔️

Details

Package	Change	Current Version	New Version	Needed Version	Looking good?
intl4x	Breaking	0.7.1	0.8.0	0.8.0	✔️
messages_shrinker	None	0.2.1	0.2.2-wip	0.2.1	✔️

Changelog Entry ✔️

Details

Package	Changed Files

Changes to files need to be accounted for in their respective changelogs.

Coverage ⚠️

Details

File	Coverage
pkgs/intl4x/build.dart	💔 Not covered
pkgs/intl4x/lib/intl4x.dart	💚 100 %
pkgs/intl4x/lib/src/collation/collation.dart	💚 100 %
pkgs/intl4x/lib/src/collation/collation_4x.dart	💚 100 %
pkgs/intl4x/lib/src/collation/collation_ecma.dart	💚 100 %
pkgs/intl4x/lib/src/collation/collation_impl.dart	💚 100 %
pkgs/intl4x/lib/src/collation/collation_options.dart	💚 20 %
pkgs/intl4x/lib/src/collation/collation_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/collation/collation_stub_4x.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/data.dart	💚 75 %
pkgs/intl4x/lib/src/data_4x.dart	💚 60 %
pkgs/intl4x/lib/src/datetime_format/datetime_format.dart	💚 100 %
pkgs/intl4x/lib/src/datetime_format/datetime_format_4x.dart	💚 17 %
pkgs/intl4x/lib/src/datetime_format/datetime_format_ecma.dart	💚 100 %
pkgs/intl4x/lib/src/datetime_format/datetime_format_impl.dart	💚 100 %
pkgs/intl4x/lib/src/datetime_format/datetime_format_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/display_names/display_names.dart	💚 100 %
pkgs/intl4x/lib/src/display_names/display_names_4x.dart	💚 5 %
pkgs/intl4x/lib/src/display_names/display_names_ecma.dart	💚 100 %
pkgs/intl4x/lib/src/display_names/display_names_impl.dart	💚 100 %
pkgs/intl4x/lib/src/display_names/display_names_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/list_format/list_format.dart	💚 100 %
pkgs/intl4x/lib/src/list_format/list_format_4x.dart	💚 17 %
pkgs/intl4x/lib/src/list_format/list_format_ecma.dart	💚 100 %
pkgs/intl4x/lib/src/list_format/list_format_impl.dart	💚 100 %
pkgs/intl4x/lib/src/list_format/list_format_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/locale/locale_4x.dart	💚 100 %
pkgs/intl4x/lib/src/number_format/number_format.dart	💚 83 %
pkgs/intl4x/lib/src/number_format/number_format_4x.dart	💚 17 %
pkgs/intl4x/lib/src/number_format/number_format_ecma.dart	💚 97 %
pkgs/intl4x/lib/src/number_format/number_format_impl.dart	💚 100 %
pkgs/intl4x/lib/src/number_format/number_format_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/plural_rules/plural_rules.dart	💚 63 %
pkgs/intl4x/lib/src/plural_rules/plural_rules_4x.dart	💚 17 %
pkgs/intl4x/lib/src/plural_rules/plural_rules_ecma.dart	💚 65 %
pkgs/intl4x/lib/src/plural_rules/plural_rules_impl.dart	💚 100 %
pkgs/intl4x/lib/src/plural_rules/plural_rules_stub.dart	💔 0 % ⬇️ NaN %
pkgs/intl4x/lib/src/utils.dart	💚 75 %
pkgs/messages_shrinker/bin/messages_shrinker.dart	💔 Not covered

This check for test coverage is informational (issues shown here will not fail the PR).

This check can be disabled by tagging the PR with skip-coverage-check

License Headers ✔️

Details

// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
no missing headers

All source files should start with a license header.

Package publish validation ✔️

Details

Package	Version	Status
package:intl4x	0.8.0	ready to publish
package:intl	0.20.0-wip	WIP (no publish necessary)
package:intl_translation	0.20.0-wip	WIP (no publish necessary)
package:messages	0.2.0	already published at pub.dev
package:messages_builder	0.2.1	already published at pub.dev
package:messages_serializer	0.2.1	already published at pub.dev
package:messages_shrinker	0.2.2-wip	WIP (no publish necessary)

Documentation at https://github.com/dart-lang/ecosystem/wiki/Publishing-automation.

[robertbastian]

Lg for the build script and collator